The present invention concerns a tower of a wind power installation for carrying a tower head of the wind power installation, comprising a flange for receiving a connection which is suitable for receiving the tower head of the wind power installation.
In conventional wind power installations, of the order of magnitude of an output of 1.0 MW and higher, the towersxe2x80x94usually these involve steel tubesxe2x80x94are of a correspondingly large and heavy nature. A flange is usually provided at the end of the tower, in the case of the steel towers. That flange forms the flat support surface of the tower for receiving an azimuth mounting, in which respect ball-type rotational connections as are known in the general art are predominantly used as the azimuth mounting. This is shown in FIG. 1.
Pre-fabricated L-flanges are frequently welded directly to the end of the tower. The L-flanges are machined so accurately with lathes that the azimuth mounting is then afforded a flat support surface. The azimuth mountings in the case of large wind power installations are of a diameter of between around 1.8 and 4.0 m (or more) and generally are of only very small structural heights of between around 50 mm and 500 mm, preferably between around 100 mm and 200 mm. Therefore those mountings require on both connection sides (tower and tower head of the wind power installation) a very flat, level and stiff connection structure. The azimuth mounting, generally therefore the ball-type rotational connection, is then screwed to the tower head on the mounting side (fitment side) of the wind power installation.
Due to the high inherent weight of the material involved, for example steel, the tower flexes in manufacture and/or in the course of subsequent transportation to the assembly location of the wind power installation. Such flexing phenomena can scarcely be avoided, in particular on uneven roads, in spite of the towers or tower elements being well supported for transportation thereof. Because of the plastic behaviour of steel, the consequence of such flexing is that the intended circular diameter of the end of the tower and of the tower generally has a tendency to change from the ideal circular shape into an oval shape (whale effect). If the circular diameter of the tower is distorted to form an oval, the flange at the end of the tower is also similarly distorted. In that situation the azimuth mounting is stressed and after some period of operation of the wind power installation, flaws and defects occur in the azimuth mounting, which is highly troublesome because repairs can only be carried out on the azimuth mounting, at very high cost and complication.
Therefore the object of the invention is to provide a tower of a wind power installation having a flange for receiving a connection, wherein the tower does not suffer deformation in respect of its cross-section, in particular in the region of the flange, by virtue of the inherent weight of the tower, during manufacture and/or transport.
That object is attained by a tower according to the invention of a wind power installation for carrying a tower head of the wind power installation, wherein the tower has a flange for receiving a connection which is suitable for receiving the tower head of the wind power installation, and the tower is characterised in that a partition or a ring bulkhead is provided in the tower interior at a spacing of preferably between 1.0 m and 7.0 m from the flange, and the partition or the ring bulkhead substantially forms a disc which is connected to the tower wall in the tower interior and which passes through the tower.
The partition or ring bulkhead in the interior of the tower provides that the tower is more difficult to deform in respect of its diameter. For, deformation of the tower diameter in the region of the partition or ring bulkhead can occur only if the ring bulkhead or partition is deformed at the same time. The partition or ring bulkhead is preferably disposed in the proximity of the flange, experience has shown that a spacing of between 1.0 m and 7.0 m is to be preferred, so that the tower diameter is stable in the region of the flange. This therefore ensures that the flange does not suffer deformation during transportation and/or manufacture of the tower.
In accordance with an embodiment a rotary mounting is used as the connection between the tower head and the tower.
The rotary mounting makes it possible for the tower head to rotate relative to the tower. In that way it is possible for the rotors of the wind power installation, which are fixed on the tower head, to be optimally oriented in relation to the wind.
An advantageous design configuration of the invention is achieved by the provision of an opening in the centre of the partition or ring bulkhead.
Articles or people can be conveyed through that opening for example by means of an elevator in the interior of the tower in the erected condition. In particular in the erection procedure or when carrying out repair operations on the wind power installation, it is frequently essential for fitters or specialist personnel with the appropriate tools to pass through the interior of the tower to the end thereof.
In accordance with a further advantageous configuration of the invention, the partition or ring bulkhead is arranged at a spacing of between 1.5 m and 3.0 m, preferably at 2.0 m, from the flange.
The partition or the ring bulkhead therefore not only affords the advantage that it ensures that the azimuth mounting enjoys a completely flat support surface, but at the same time it can also serve as a mounting platform if the tower of the wind power installation, after erection, is to receive the tower head, that is to say the pod, in other words the machine carrier of the wind power installation with the generator and the rotor. For that purpose it is necessary for fitter operatives to move the machine carrier from the interior to the end of the tower and to carry out operating procedures on the machine carrier. The partition or bulkhead according to the invention affords the fitters a safe and secure working platform which can also always be used again in subsequent working operations and which then no longer has to be set up in position.
In accordance with a development of the invention there are provided further partitions or ring bulkheads in the interior of the tower, which each substantially form a disc which is connected to the tower wall in the tower interior and passes through the tower.
The plasticity of the tower is reduced in the region of the additional partitions or bulkheads, with each further partition or ring bulkhead. Accordingly, the provision of further partitions or ring bulkheads in the tower interior affords the advantage that the ideal cross-sectional shape of the tower can be maintained over wide regions of the tower.